Corrosion inhibitor for vanadium-containing fuels

ABSTRACT

This invention relates to a composition containing calcium and aluminum, preferably in the ratio Ca/3Al, or calcium and aluminum in combination with Si, preferably in the ratio between about Ca/3Al/2Si and Ca/3Al/4Si (all calculated as metal weights); and to the use of such composition in petroleum fuels which contain vanadium, particularly in combination with sodium, for example in residual fuels so as to inhibit corrosion in the system, particularly in gas turbines. These compositions are superior to magnesium as an additive to such fuels, particularly in fuels which are high in sodium.

i nited States Patent [191 Zetlmeisl et al.

[ Dec. 16, 1975 CORROSION INHIBITOR FOR VANADIUM-CONTAINING FUELS [75]Inventors: Michael J. Zethneisl; Walter R.

May; Robert R. Annand, all of St.

Louis, Mo.

[73] Assignee: Petrolite Corporation, St. Louis,

[22] Filed: Aug. 6, 1973 [21] Appl. No.: 386,228

[52} US. Cl. 44/51; 44/67; 44/DIG. 3; 252/387 [51] Int. Cl. C10Ll/32;C1OL 1/12;C1OL l/3O [58] Field of Search 44/51, 67, DIG. 3; 252/387[56] References Cited UNITED STATES PATENTS 3,036,901 5/1962 Sanders etal. 44/67 X 3,628,925 12/1971 Milner 44/51 X FOREIGN PATENTS ORAPPLICATIONS 745,012 2/1956 United Kingdom Primary Examiner-Delbert E.Gantz Assistant Examinerl. Vaughn Attorney, Agent, or Firm-Sidney B.Ring; Hyman F. Glass [5 7] ABSTRACT 10 Claims, 1 Drawing FigureCORROSION INHIBITOR FOR VANADIUM-CONTAINING FUELS The demand for greatlyincreased amounts of energy has forced utilities and otherlarge-quantity .usersof fossil fuels to explore low-quality fuels foruse in steam boilers and gas turbines. Fuels such as unrefined crude oiland residual oil contain large amounts of impurities which result incorrosive deposits in the equipment. Two of these impurities, sodium andvanadium, form catastrophically corrosive, low melting slags that candestroy a vital part in a matter of hours.

Crude oil usually contains 1-500 ppm of vanadium in the form of aporphyrin complex depending on the source. Because of its origin as aconcentrate from the refining process, residual oil contains severaltimes more vanadium than the crude from which it was derived. Thecombustion of these vanadium-containing fuels produces very corrosive Vdeposits which can destroy a turbine part in a matter of days. Althoughthe vanadium can be removed, the cost of the process cancels theeconomic advantage of using unrefined fuels. Vanadic corrosion is,therefore, usually controlled with chemical additives and optimizationof operating conditions.

Sodium is almost always present in low-quality fuels, either directly inthe crude oil or indirectly through contamination from various sources.The technology for removing sodium is well developed. These are limitingprocesses, however, and a trace of sodium must always be dealt with. Forexample, in maritime use the sodium level can be increased because ofthe introduction of sodium chloride through the air intake andcontamination of the fuel by sea water. During combustion, the sodiumreacts with the sulfur in the fuel to form the sulfate which isdeposited in turbine parts.

This reaction has been shown to be thermodynamically favored and resultsin the only sodium compound that will deposit under these conditions.

The mechanism of corrosion by vanadium and sodium has received muchattention. Nascent oxygen species has been proposed as the corrosiveactive agent in V 0 melts. Various mechanisms have been presented toexplain corrosive attack by sodium sulfate at metal surfaces. Theclassical method of inhibiting the corrosive characteristics of V 0 andNa SO melts has been to form high-melting vanadates of the former andminimize the level of the latter. Magnesium has been the most successfulsubstance for this type of protection. The optimum levels of magnesiumaddition are not precisely known. Just as the mechanism of corrosion isonly partially understood, so too is that of its inhibition.

There are other methods of limiting the corrosion such as reducing theoperating temperature and maintaining the air to fuel ratio so thatslightly reducing conditions exist during combustion. These types ofmethods may not be applicable. For example, the air to fuel ratio cannotbe lowered to obtain reducing condi tions in a gas turbine. Loweroperating'temperatures make the system less efficient and may. be ruledout for I economic reasons. Thus, chemical additives are oftenvturbines, steam boilers and furnaces. This invention comprises theaddition of calcium and aluminum, or

calcium and aluminum in combination with silicon, to

2 the fuels. We have discovered that Ca/Al additives are not onlyeffective as compared to magnesium, the standard for the industry, butthat Ca/Al also allows the fuel system to tolerate a sodium to vanadiumratio 10 times greater than when magnesium is employed.

We have further discovered that the use of silicon with Ca/Al furtherimproves the 'system, particularly in view of the fact that it yields aslag which is more friable, water washable and more easily removed.

In practicing this invention, optimum results are achieved where theCa/Al weight ratio is /a calculated as metal weights. Although otherratios can be employed such as V2, for example H25, and as low as A, theimprovement of this invention is optimized at about the A; ratio.

Where silicon is employed, the same ratios of Ca/Al inter se areemployed with silicon added thereto. Optimum results are achieved wheresilicon is about 50% of the Ca/Al/Si mixture. Lesser amounts can also beemployed such as where Si is as little as 1%, such as 25%, of themixture, and as high as 99%, such as and preferably from 40 to 60%.

The corrosion rates of materials used in gas turbine, furnace and steamboiler construction in sodiumvanadium-sulfur containing slags may bedetermined by a variety of methods. The most reliable method is a fieldtest in operating equipment. However, because of the costs involved, avariety of tests have been designed to either duplicate or reflectactual field conditions. These range from high-pressure test rigs whichare similar to gas turbines on a smaller scale to simple crucible testscarried out in a laboratory muffle furnace. We have developed anelectrochemical technique for measuring corrosion rates in a laboratoryscale furnace that accurately reflects the situation observed in largertest facilities and in the field. This technique is described in thearticle High-Temperature Corrosion in Gas Turbines and Steam Boilers byFuel Impurities. 1. Measurement of Nickel Alloy Corrosion Rate in MoltenSalts by Linear Polarization Technique, by Walter R. May, et. al.,Industrial and Engineering Chemistry, Product Research and Development,Vol. 1 1, No. 4, pg. 438, 1972. The data presented below in support ofthis disclosure was obtained by this technique. Good correlation hasbeen found between data from this test and field data. Data on magnesiumare published in the articles High-Temperature Corrosion in Gas Turbinesand Steam Boilers by Fuel Impurities. II. The Sodium Sulfate-MagnesiumSulfate- Vanadium Pentoxide System and Ill. Evaluation of Magnesium as aCorrosion Inhibitor, Industrial and Engineering Chemistry, Vol. 12, No.2, pgs. l40l49, 1973.

Corrosion rate data taken in this manner on the Na SO,CaSO -AI O V Osystem are presented in Table I. For comparison, similar data formagnesium are presented in Table II.

From these data, it can easily be seen that in the calcium-aluminumsystem, the Na/V ratio can be tolerated at 10 times the level for themagnesium system. For example, compare Mg/V=4 and Na/V=0.l in Table IIwith Ca/V=0.79, Al/V=3 and Na/V=l in Table I. At 900C, corrosioncurrents of 0.0438 mg/in.-hr. were obtained for aluminum-calcium whereas0.230 mg/in.-hr. was obtained in the magnesium system. We considered0.05 mg/in.-hr., which corresponds to 10 mpy for Udimet 500, the maximumpermitted corrosion rate. A similar table of data are presented in Table111 for the calcium-aluminum-silicon system. From these data, the FIGUREof this invention was drawn.

Table I Corrosion Rates for Udimet 500 in Various Na SO CaSO SiO Al O;,VO Compositions Ratio Mole Percent corr(ma/cm"')* Na/V Ca/V Al/V Nil-2S0;CaSO A1 V 0 800 850 900 950 l 0.79 1 31.15 28.26 26.54 14.05 16.4 17.326.7 35.3 1 1.58 1 24.29 44.07 20.70 10.95 37.2 54.8 1 0.79 2 24.6222.33 41.95 11.10 .768 1.14 1.82 2.79 l 1.58 2 20.12 36.51 34.29 9.07.891 1.78 3.01 4.13 1 0.79 3 20.35 18.46 52.02 9.17 5.56 6.95 9.73 14.41 2.37 1 19.90 54.16 16.96 8.97 3.67 6.73 11.6 20.2 1 1.58 3 17.18 31.1743.91 7.75 .303 .440 .586 .879 1 2.37 2 17.02 46.31 29.00 7.67 .74 1.01.66 35 1 2.37 3 14.86 40.45 37.99 6.70 .263 .323 .404 .404 1 0.23 0.7241.92 13.46 25.72 18.90 14.28 17.8 20.3 24.2 1 0.56 1.44 22.38 40.0627.46 10.09 2.21 2.80 5.9 12.3 1 0.84 2.16 23.50 22.65 43.25 10.60 1.693.98 4.94 6.78 1 1.12 2.88 19.27 24.76 47.28 8.69 .522 1.42 1.86 2.39 11.40 3.60 16.33 26.22 50.09 7.36 1.41 2.75 3.57 4.98 l 2.80 7.20 9.2629.75 56.82 4.18 .0206 .0374 .0975 167 l 5.60 14.40 4.96 31.89 60.912.24 .0393 .0524 .0655 .0712 1 8.4 21.6 3.39 32.68 62.41 1.53 .0398.0507 .0602 0708 1 11.2 28.8 .57 33.03 63.18 1.16 .0267 .032 .0533 .0561 14.0 36.0 2.08 33.33 63.66 0.94 .0160 .0173 .0240 .0267 0.1 0.79 14.33 39.27 36.88 19.52 .246 .325 .396 .476 0.1 1.58 1 3.11 56.39 26.4814.01 .153 .223 .282 .388 0.1 0.79 2 3.16 28.69 53.89 14.26 .0206 .0311.0362 .0621 0.1 1.58 2 2.46 44.58 41.88 11.08 .0177 .0442 .0618 .09730.1 0.79 3 2.49 22.60 63.68 11.23 .035 .0524 .0438 0874 0.1 2.37 1 2.4265.98 20.66 10.93 .0516 .0688 .124 .206 0.1 1.58 3 2.03 36.87 51.94 9.16.0115 .0345 .0574 .0688 0.1 2.37 2 2.01 54.69 34.24 9.06 .0208 .0249.0332 .0457 0. 2.38 3 1.71 46.76 43.80 7.73 .0115 .0087 .0115 .023 0.010.79 1 0.45 40.86 38.38 20.31 1.04 1.51 1.67 1.98 0.01 1.58 1 0.32 58.0227.25 14.42 .042 .053 .111 .126 0.01 0.79 2 0.33 29.53 55.47 14.68 .0243.0388 .0630 .0873 0.01 1.58 2 0.25 45.59 42.83 11.33 .0138 .0166 .02210276 0.01 0.79 3 0.25 23.12 65.14 11.49 .0357 .0536 .0714 119 0.01 2.371 0.25 67.46 21.12 11.18 .074 .108 .133 .207 0.01 1.58 3 0.21 37.5552.91 9.33 .0192 .0240 .0335 .0478 0.01 2.37 2 0.20 55.69 34.87 9.23.0084 .0126 .0210 .0335 0.01 2.37 3 0.17 47.42 44.54 7.86 .0088 .0131.0175 .0526 0.001 0.79 1 0.05 41.03 38.54 20.39 1.35 1.81 2.32 2.920.001 1.58 1 0.03 58.18 27.33 14.46 .257 .322 .354 .386 0.001 0.79 20.03 29.61 55.63 14.72 .054 .049 .081 .086 0.001 1.58 2 0.03 45.70 42.9211.36 .085 .058 .044 .041 0.001 0.79 3 0.03 23.17 65.29 11.52 .0047.0071 .0094 .024 0.001 2.37 1 0.02 67.61 21.17 11.20 .349 .436 .653 .8280.001 1.58 3 0.02 37.62 53.01 9.35 .096 .036 .0598 .0683 0.001 2.37 20.02 55.80 34.94 9.24 .0276 .0328 .0493 .0766 0.001 2.37 3 0.02 47.5044.62 7.87 .0396 .0509 .0736 .125

Some of the corrosion rate data are given as corrosion currents tma/cm")and some as corrosion rates lmg/cm -hr). The conversion from corrosioncurrent to corrosion rate for L'dimet 500 is 0.95. Within theexperimental limitations of the procedure. the two values can beconsidered identical.

Table 11 Corrosion Rate for Udimet 500 in Various Na;,SO MgSO V OCompositions from 800 to 950 M01 7( Wt ratio Corrosion rate. mg/cm hr NaSO MgSO V 0 Mg/V Na/V 800 850 900 950:

' Table 1Icontinued Corrosion Rate for Udimet 500 in Various Na; SO-MgSO V:O;, Compositions from 800 to 950 M01 71 Wt ratio Corrosion rate.mg/cm" hr 198 50 MgSO, V Mg/V Na/V 800 850 900 950 Table III CorrosionRates for Udimet 500 in Various Na SO CaSO SiO -A1 O;,V O CompositionsRatio Mole Percent 'corr (ma/em Na/V Ca/V Si/V A1/V Na SO CaSO. S10 A1 0V 0 800 850 900 950 1 l 1 1 19.655 22.549 32.178 16.748 8.870 1.99 3.806.52 9.23 1 2 1 1 16.039 36.800 26.257 13.666 7.238 3.75 5.63 8.36 15.181 1 2 1 14.870 17.059 48.689 12.670 6.711 .623 .917 1.51 2.01 1 1 1 216.836 19.314 27.562 28.690 7.598 .277 .501 .983 1.37 1 2 2 1 12.70329.146 41.593 10.824 5.733 .859 1.38 2.28 2.54 1 2 1 2 14.111 32.37523.100 24.046 6.368 .093 .170 .266 .368 1 1 2 2 13.198 15.141 43.21322.491 5.956 .0145 .027 .029 .228 1 2 2 2 11.463 26.300 37.531 19.5345.173 .149 .166 .236 .323 0.1 1 1 1 2.388 27.395 39.094 20.347 10.777.24 .32 .37 .40 0.1 2 1 1 1.874 43.008 30.687 15.972 8.459 .626 .793.834 .876 0.1 1 2 1 1.717 19.695 56.212 14.628 7.748 .0195 .0226 .0329.0534 0.1 1 1 2 1.984 22.763 32.484 33.814 8.955 .0180 .0235 .0271 .03070.1 2 2 1 1.434 32.909 46.963 12.221 6.473 .109 .143 .176 .193 0.1 2 1 21.616 37.085 26.461 27.544 7.294 .0573 .0823 .107 .129 0.1 1 2 2 1.49817.182 49.638 25.523 6.759 .0184 .0258 .0268 .0478 0.1 2 2 2 1.27829.325 41.848 21.781 5.768 .0250 .0293 .0368 .0498 0.01 1 1 1 0.24427.996 39.952 20.794 11.013 .0643 .0643 .0643 .0944 0.01 2 1 1 0.19143.746 31.214 16.246 8.605 .0367 .0496 .0648 .0906 0.01 l 2 1 0.17420.004 57.094 14.857 7.869 .0231 .0370 .0703 .0795 0.01 1 1 2 0.20223.177 33.075 34.429 9.1 18 .0042 .0053 .0084 .0148 0.01 2 2 1 0.14533.339 47.577 12.381 6.558 .0218 .0294 .0348 .0533 0.01 2 1 2 0.16437.632 26.851 27.951 7.402 .0218 .0283 .0468 .0698 0.01 1 2 2 0.15217.417 49.708 25.872 6.851 .002 .002 .003 .0042 0.01 2 2 2 0.129 29.66642.335 22.034 5.835 .0109 .0153 .0174 .0218 0.001 1 l 1 0.024 28.05840.040 20.840 11.038 .0717 .0942 .127 .156 0.001 2 l 1 0.019 43.82131.267 16.274 8.619 .0235 .0326 .0428 .0612 0.001 1 2 1 0.017 20.03657.184 14.881 7.882 .0117 .0117 .0117 .0176 0.001 1 1 2 0.020 23.21933.135 34.491 9.134 .0089 .0133 .0192 .0258 0.001 2 2 1 0.015 33.38347.639 12.397 6.566 .0324 .0392 .0579 .0682 0.001 2 1 2 0.016 37.68826.891 27.992 7.413 .0235 .0326 .0428 .0612 0.001 1 2 2 0.015 17.44049.776 25.907 6.861 .00033 .00131 .0033 .0033 0.001 2 2 2 0.013 29.70142.384 22.060 5.842 .0022 .0025 .0025 .0031

-cont1nued The following series of equatlons approx1mate the Fora/3All/2 pans addih-FMVH 5 ma] amount of additive to be employed at 900C.All values for the additives and metal weights are in ppm.

65 Note the following. First, these equations will give only a fairlyclose approximation of the required dos- For Mg: parts additive=41V1+ 40N FmMg/Si: Pam uddmvefllvh 8U age. Secondly, the equatlons seem to workfor h1gh {N vanadium levels only when the sod1um levels are also ForCa/S A1: parts additive=3IVl+ 15 7 fairly high. Since such highvanadium-sodium levels will be seldom encountered, if ever, fitting thedata for lower vanadium levels is clearly more useful.

In practice, for fuels containing low vanadium, i.e. V up to 12 ppm andNa up to ppm. one employs up to 100 ppm of the additives of thisinvention, such as to 80 ppm, but preferably no more than 70 ppm.

When the fuels contain high vanadium, i.e. V over 12 ppm and Na up to 5ppm. one employs about 50 to 2500 ppm, such as from about 70 to 2000 ppmbut preferably from about 100 to 1500 ppm.

Table IV Dosage for Particular Crude Oils Containing Vanadium at SeveralNa Levels Additive (ppm) Crude Vlppm) Na Levekppm) Mg Mg Si Ca 3 Al Cu 3A1 2 Si Abu Dhabi 11.5 .05 8-9 13-15 3.6-5 3.2-5 (Mid East) .15 13-155-7 4.2-6

.5 23-30 60 10-11 7-9 1.5 60 150 22-24 15 5 150-200 =300 70 70 ArabianLight 12 .05 36 57.6 31.2

. 15 54 84 32.4 32.4 .5 77 144 40.8 38.4 1.5 144 252 60 50.4 5 300 600108 78 East Texas Cretaceous 4 .05 17 28 10 10.4 .15 28 44 10.4 12.8 .548 84 19.2 16.8 1.5 92 224 32 24 5 220 480 76 52 Bachaquero 413 =4501280 1033 1074 (Venezuela) .15 620 1404 1033 1074 .5 826 1652 1033 11151.5 1074 1900 1033 1115 5 1735 2891 1115 1115 Bose-an 900 .05 900 =27002250 340 (Venezuela) .15 1080 2880 2250 340 1530 3240 2250 340 1.5 19803600 2250 340 5 2880 4500 2340 2340 El Alamein 15 .05 39 67.5 37.5 37.5(Egypt) 15 60 94.5 37.5 39.0 .5 17.5 150 46.5 48.0 1.5 165 270 66 60 5315 600 1 13 90 Gabon 4-10 .05 18-31 28-50 1 1-26 1 l-25 (Africa) .158-48 44-70 13-28 13-28 .5 48-80 84-120 19-34 17-34 1.5 104-130 184-23032-50 4-40 5 260-27 0 500-600 76-100 5 0-70 Kuwait 60 .05 108 228 150156 (Neutral Zone) .15 360 258 150 156 .5 228 360 150 162 1.5 360 540180 180 5 600 960 240 228 Lih \'a. Es Sider 2.5 .05 13 20 7.5 7.5 15 2234 9.5 8.5 .5 15 1 3 1.5 45 163 27.5 18 5 200 500 45 Louisiana. 1 .05 813 3.6 3.2 Typical 15 13 25 5 4.2

.5 23 10 7 1.5 60 150 22 1 5 5 150 300 Minus. 0.4-0.7 5-7 9-1 1 2-3 2Sumatra .15 9-1 1 19-21 3 3-4 .5 22-24 30-53 8-9 5-6 1.5 64-60 128-13320-21 15-21 5 280-224 360-392 70-100 -100 Nigeria. 0 3-4 05 4-18 6-283-11 2-11 Various .15 8-28 18-44 3-13 2-13 .5 21-48 45-84 7-19 5-17 1.566-104 -184 21-32 24 5 300-260 300-500 120-76 =120-50 North Slope 12-16.05 36-43 57.6-72 31.2-38.4 30-41.6 (Alaska) .15 54-64 84-96 324-38432.4-41.6

.5 77-104 144-160 40.8-51.2 38.4-48 1.5 144-168 252-272 60-7 50.4-64 5300-336 600-640 108-119 78-896 Quatar 10-20 .05 31-50 50-84 26-48 26-52(Midwest) 15 48-72 50-112 28-50 28-52 .5 80-120 120-180 34-60 34-60 1.5-190 230-300 50-80 40-72 5 270-360 600-680 100-130 70-100 Dosage forParticular Crude Oils Containing Vanadium at Several Na Levels Additive(ppm) Crude V(ppm) Na Level(ppm) Mg Mg Si Ca 3 A1 Ca 3 Al 2 Si Redwash 1.05 8 1 3 3.9 3.4 (Utah) .15 13 23 5 4.2

.5 28 56 7 1.5 65 I50 22 5 200 70 80 Redwater 0.5-4.5 .05 5.5-19 9-302-13 2-13 (Canada) .15 10-30 12-45 4-15 3-14 .5 22-50 -86 8-18 5-18 1.5-95 125-180 20-30 20-26 5 250-225 325-495 90-770 100-900 Smackover 1 .058 1 3 3.9 3.4 (Arkansas) .15 13 23 5 4.2

.5 28 56 10 7 1.5 65 151] 22 15 5 200 40' Wilmington 50 .05 200 (LA.Basin) .15 185 220 125 130 .5 200 315 130 130 1.5 325 500 155 5 550 5000220 200 In actually treating one of the fuels mentioned in Table 1,approximately 25-30% less additive will be 25 homogeneity is achieved.30

The silicon content has been found to affect the corrosion rates onlyslightly and silicons main function is to provide a more friable andremovable slag. The optimum silicon content was determined by means of asimple burner test in which fuel with additive and con- 35 taminants(Na, V, S) was atomized into a pilot flame and the combustion productsimpinge on a metal target at an appropriate distance in the flame tomaintain a temperature of 900C. This test is described in more detail inthe paper High-Temperature Corrosion in Gas Turbines and Steam Boilersby Fuel Impurities. 1V. Evaluation of Silicon and Magnesium-Silicon asCorrosion Inhibitors," to be presented at the American Society ofMechanical Engineers meeting, Detroit, Michigan, Nov. 1973.

Data from the slag test for Mg-Si and Ca-Al-Si are compared in Tables Vand V1. It can be seen from these data that CaAl-Si system withCa/V=0.75, A1/V=2.25 and Si/V=3 forms the most friable and easilyremoved slag.

Table V Slag Data on MgSi with Mg/V=3 and Si/\/ Varying Avg. 7: LostNa/V Mg/V Si/V Wt. Deposit Wt. Deposit/SA. 71 Lost on Brushing onBrushing .l 3 1 5.0 .924 10 ll 2 l 3 1 7.1 1.31 0 2.5 3 l 7.2 1.41 0 0 32 7.0 1.25 20 Table VI Slag Data on Ca-Al-Si Avg. "/2 Loss Na/V Ca/VAl/V Si/V Wt. Deposit W1. Deposit/SA. i Loss on Brushing on Brushing Itwill be apparent that various changes and modifica- 25 into said fuels aminor but effective amount of the tions may be made in this inventiondescribed herein composition of claim 1. without departing from thescope of this invention. It is 7. A process of inhibiting corrosion invanadium-conintended therefore that all matter contained herein tainingpetroleum fuels which comprises incorporating shall be interpreted asillustrative and not as limitative. into said fuels a minor buteffective amount of the What we claim is: composition of claim 2.

l. A composition of matter consisting essentially of 8. A process ofinhibiting corrosion in vanadium-concalcium and aluminum in a weightratio of Ca/Al of taining petroleum fuels which comprises incorporatingabout /3i2 calculated as metal weights. into said fuels a minor buteffective amount of the 2. The composition of claim 1 which alsocontains composition of claim 3. silicon. 3 5 9. A process of inhibitingcorrosion in vanadium-con- 3. The composition of claim 2 where siliconconstitaining petroleum fuels which comprises incorporating tutes l99%of the composition. into said fuels a minor but effective'amount of the4. The composition of claim 1 where the ratio of composition of claim 4.

Ca/Al is about A2. 10. A process of inhibiting corrosion in vanadium- 5.The composition of claim 3 where the ratio of 40 containing petroleumfuels which comprises incorpo- Ca/Al/Si is about U l/2 to l/4/5. ratinginto said fuels a minor but effective amount of 6. A process ofinhibiting corrosion in vanadium-conthe composition of claim 5. tainingpetroleum fuels which comprises incorporating

1. A COMPOSITION OF MATTER CONSISTING ESSENTIALLY OF CALCIUM ANDALUMINUM IN A WEIGHT RATIO OF CA/AL OF ABOUT 1/3$2 CALCULATED AS METALWEIGHTS.
 2. THE COMPOSITION OF CLAIM 1 WHICH ALSO CONTAINS SILICON. 3.The composition of claim 2 where silicon constitutes 1-99% of thecomposition.
 4. The composition of claim 1 where the ratio of Ca/Al isabout 1/3 .
 5. The composition of claim 3 where the ratio of Ca/Al/Si isabout 1/1/2 to 1/4/5.
 6. A process of inhibiting corrosion invanadium-containing petroleum fuels which comprises incorporating intosaid fuels a minor but effective amount of the composition of claim 1.7. A process of inhibiting corrosion in vanadium-containing petroleumfuels which comprises incorporating into said fuels a minor buteffective amount of the composition of claim
 2. 8. A process ofinhibiting corrosion in vanadium-containing petroleum fuels whichcomprises incorporating into said fuels a minor but effective amount ofthe composition of claim
 3. 9. A process of inhibiting corrosion invanadium-containing petroleum fuels which comprises incorporating intosaid fuels a minor but effective amount of the composition of claim 4.10. A process of inhibiting corrosion in vanadium-containing petroleumfuels which comprises incorporating into said fuels a minor buteffective amount of the composition of claim 5.